更新2

woocommerce_email_recipient_{$email_id}过滤器是一个复合钩子，在其中设置的正确的电子邮件ID是customer_on_hold_order而不是customer_on_hold_order_order，这将不起作用…

The woocommerce_email_recipient_{$email_id} filter is a composite hook and the right email ID to set in it is customer_on_hold_order and not customer_on_hold_order_order which will not work…

使用WC_Order对象，从Woocommerce 3开始，您需要使用

With the WC_Order object, since Woocommerce 3, you need to use get_payment_method() method.

为避免除"Bacs"付款方式外的客户保留"电子邮件通知，请使用:

To avoid Customer ON Hold email notification except for "Bacs" payment method use:

add_filter( 'woocommerce_email_recipient_customer_on_hold_order', 'customer_on_hold_order_for_bacs', 10, 2 );
function customer_on_hold_order_for_bacs( $recipient, $order ) {

    if( is_a('WC_Order', $order) && $order->get_payment_method() !== 'bacs' ){
        $recipient = '';
    }
    return $recipient;
}

代码进入您的活动子主题(活动主题)的function.php文件中.经过测试，可以正常工作.

Code goes in function.php file of your active child theme (active theme). Tested and works.